Block link with integral bushing



Jan. 28, 1964 N. E. PEARSON BLOCK LINK um. INTEGRAL ausamc FilQd NOV. 13, 1961 United States Patent 3,119,276 BLOCK LINK WlTH lNTEGRAL BUSHING Nels E. Pearson, Evergreen Park, Ill., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Filed Nov. 13, 196i, Ser. No. 151,815 Claims. (1. 74-450) This invention relates to sprocket chain of stamped construction and particularly to a block link of improved and integral construction.

According to the invention, the bottom side of the block link includes webs which join the bottom edges of the side bars of the block link with the ends of the barrels extending between the bars. The bottom side of each barrel and the webs at the ends of the barrel directly and rigidly join the bars. The bottom side of the link and barrels refers to the side which is engaged by the drive sprocket. The top sides of the barrels are open and the ends of the barrels are spaced from the bars to minimize the amount of material which will or can collect in the barrel.

The chain is particularly intended for agricultural rnachines where the material causes or promotes rusting of the metal. After a long period of standing, the rusted joints of ordinary chain are frequently so tight that the chain breaks when the machine is started up.

The barrels of the block link of the present invention have some flexibility which allows them to expand slightly with the first turning movement of the pins and in that way the pins are then freed for turning before any chain damage can occur with chain movement in either direction. Accordingly, if the machine is allowed to stand without protecting the chain against rusting, the joints of the chain may become tight but when operation of the machine is resumed no damage to the chain will occur.

The chain is operated so that in moving around the sprockets the material tends to be thrown centriiugally out of the bushings through the gap provided.

The webs which connect the barrels with the side bars of the link provided the link with the rigidity and strength which is required.

In he operation of the chain in either direction, the barrels support the block on the sprocket and the teeth of the sprocket engage the barrels to drive the chain.

The pressure of the sprocket tooth against the face of the barrel is partly applied directly to the pin and partly through the webs to the side bars which are disposed adjacent to the bars of the next link. Accordingly, the pin is trapped or held and supported between the barrel so that the pin is not overloaded.

In addition to providing the features described, it is also an object of the invention to provide an improved chain of a construction which is less expensive than that presently available or known.

The drawings furnished herewith illustrate the best mode of carrying out the invention as presently conternplated and set forth hereinafter.

In the drawings:

FIGURE 1 is a plan view of the blank from which the block link is formed;

FIG. 2 is a plan view of the top side of the block link and parts of the adjacent pin links which comprise the chain;

FIG. 3 is section of the block link shown in FIG. 2 taken on lines 33 thereof;

FIG. 4 is a plan view of the bottom or sprocket side of the block link shown in FIG. 2; and

FIG. 5 is a side elevation of a part of a drive sprocket and the chain in operation thereover with the links of the chain shown in section.

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The block link 1 embodying the present invention is shown in the drawing between the pin link 2 and the at tachment link 3 which are shown in part.

Pin link 2 comprises the plates 4 and a pin 5 which extends through corresponding holes in each end of the plates. The headed ends 6 of pins 5 overlie plates 4 to secure the plates on the pins. As in most chain, pins 5 are fitted tightly in the holes of plates 4 to prevent rotation of the pins in plates 4 and so that each pin link 2 comprises a rigid assembly. The attachment link 3 is similar to link 2 except that the pin plate 4a is provided, for example, with the extending flange 8 to which a conveyor flight or the like, not shown, may be attached.

The block link 1 connecting the links 2 and 3 is of stamped, unitary construction and includes the plates 11 having holes 12 at their ends through which the pin 5 of the adjacent pin link extends and in which the pin is turnable. The barrels of each link 1 include the sides referred to hereinafter as the pin supports 13 and the bottom Webs 14. Pin supports 13 and webs 14 form U-sections disposed with the open side facing away from the drive sprocket over which the chain is to operate.

The ends of webs 14 are integrally formed and com nected with the respective plates 11 as at Ma and webs 14 are disposed to engage directly the sprocket 16 between teeth 17, as shown.

The link 1 is readily blanked from fiat steel stock in the form shown in FIGURE 1 with supports 13 comprising rectangular tabs extending in opposite directions. The holes 1211 as pierced in the blanking operation are smaller than the final holes 12 and the final holes are drilled after the link is formed from the blank. The final forming of the holes after forming the link is preferable where the thickness of the material of the link requires a large radius at Ma between plates 11 and the webs 14 which are adjacent to the holes.

The pin supports 13 are provided instead of the usual closed bushing which latter involves more cost than is allowed where there is to be only seasonal use of the chain.

Adequate pin strength is provided according to the present invention by forming the blank from strip steel material which has been rolled so that the grain of the metal in pin supports 13 runs parallel to the pins and by forming the supports so that their sides hold the pin therebetween With a light pressure.

The supports thereby have sufficient flexibility to allow the pin to free itself in case of severe rusting, but have adequate lengthwise rigidity to support the pin against the pressure applied thereto by the teeth 17 of sprocket 16.

In the operation of the chain over sprocket 16, the pressure applied by the teeth 17 is transmitted to side bars 11 jointly by webs 14 at 14a and through supports 13 and pins 5. For such operation, the supports 13 associated with each pin are spaced to trap the pin therebetween. The engagement of pins 5 by supports 13, however, is yieldable and in case of rusting, as mentioned, the pin will readily free itself rather than turn in pin plates 4. Such turning in plates 4 is not desired because of the small bearing area afforded by the plates. Also, when pins 5 become turnable in plates 4, the links 1 and 3 are no longer rigid and the chain is very likely to run oil from the sprockets. The rigidity of link 1 is maintained at all times by reason of the improved integral construction.

Various embodiments of the invention may be employed within the scope of the accompanying claims wherein the term barrels refers to the U-sections formed by webs l4 and pin supports 13.

I claim:

1. A block link of stamped integral construction for conveyor or drive chain having a sprocket-engaging side and a top side and comprising parallel, spaced side bars, parallel spaced barrels extending between said bars, the top side of said barrels having full-len th openings and webs joining the ends of the barrels opposite said openings and the edges of the bars on the sprocket-engaging side of the link, said bars having holes in alignment with said barrels for receiving the pins of the adjacent link.

2. In a sprocket chain for agricultural use or the like and including pin links and block links interconnected by round pins turnable in the block links, each block link being of stamped, integral construction and having a sprocket-engaging side and a top side, said block link comprising parallel, spaced side bars, parallel, spaced barrels extending between said bars, the top side of said barrels having full-length openings and webs joining the ends of the barrels opposite said openings and the edges of the bars on the sprocket-engaging side of the link, said bars having holes in alignment with said barrels for receiving the pins of the adjacent link, said openings allowing the discharge of material from or precluding the accumulation of material in the barrels and said barrels being expandable so that normal chain movement can break any locking of the pin in the barrel er ected by the products of corrosion.

3. The invention of claim 1 wherein the link is formed of a hot-rolled steel having a grain running cross-Wise of the link and length-wise of the barrels for maximum pin support.

4. A block link for joining two pin links in a chain for operation over a sprocket and of integral, stamped construction including spaced, parallel side bars (11) having holes (12) in each end for receiving the pins of the adjacent pin links and spaced, parallel barrels wherein each barrel comprises:

a central section or web (14) having ends (14a) joined to the edges of the bars adjoining the holes in the bars and on the sprocket side of the chain, and

pin supports (13) extending from said webs on each side thereof between bars and having limited flexibility and a space therebetween on the side of the chain opposite the sprocket side of the chain for the improved serviceability of the chain as described.

5. In a chain having alternate block links and pin links for operation over a sprocket, a block link of stamped construction including spaced, parallel side bars and spaced parallel Webs joining the side bars to define an opening on one side of the chain for receiving the tooth of a sprocket, each said web being of a curved M section for fitting the pocket of the sprocket between adjacent teeth, and pin supports extending from each web and having ends spaced from the side bars, the supports of each Web being of a curved section to engage the corresponding pin of the adjacent pin link and extending away from said opening on said side of the chain.

References Cited in the file of this patent UNITED STATES PATENTS 2,272,837 Getz et al. Feb. 10, 1942 2,440,212 Schmidt Apr. 20, 1948 FOREIGN PATENTS 282,591 Switzerland Aug. 16, 1952 

1. A BLOCK LINK OF STAMPED INTEGRAL CONSTRUCTION FOR CONVEYOR OR DRIVE CHAIN HAVING A SPROCKET-ENGAGING SIDE AND A TOP SIDE AND COMPRISING PARALLEL, SPACED SIDE BARS, PARALLEL SPACED BARRELS EXTENDING BETWEEN SAID BARS, THE TOP SIDE OF SAID BARRELS HAVING FULL-LENGTH OPENINGS AND WEBS JOINING THE ENDS OF THE BARRELS OPPOSITE SAID OPENINGS AND THE EDGES OF THE BARS ON THE SPROCKET-ENGAGING SIDE OF THE LINK, SAID BARS HAVING HOLES IN ALIGNMENT WITH SAID BARRELS FOR RECEIVING THE PINS OF THE ADJACENT LINK. 